Adaptive Control of High Precision Positioning Stages with Friction

The presented work concerns an adaptive model-based control scheme for a two dimensional high precision positioning stage. The proposed structure consists of an integral state space controller and a disturbance observer. The system model of the state space controller represents the inertia as well as the friction force in a reduced way. The parameters of the friction model are updated online to calculate motion dependent controller gains. With this procedure a considerable reduction of the tracking error is possible. The developed model-based control scheme is used for one axis of the positioning stage. An experimental study demonstrates the performance of the adaptive state space controller with observer at several trajectories. The results show that the system's dynamical behavior can be improved significantly.